It's curious that the QR code is defaced. I wonder why. The screen suction cup wasn't needed and I soon had the battery replaced.
Instructions on how to replace your battery are widely available on YouTube. I watched this one.
It remains to be seen what effect this has (the battery came virtually discharged). It was an easy and cheap process.
I'm very happy with the new battery. At the end of of a day of normal use I was getting the 20% warning, today (after a full charge over night) I'm still at 89%. It's like having a new phone again for $9.